Carburetor structure



A. R. NELSON 7' CARBURETOR STRUCTURE fDec. 28 1926.

Filed March 5 Im/e nbor Fij Z witness Patented Dec. 28, 1,926.

UNirEo STAT-ES PATENT. orrica.

anvrn n. NELSON, or manarnon, Iowa.

camzunn'ron STRUCTURE.

Application filed March 5, 1923. Serial No. 622,797.

My invention has to do with a carburetor simultaneously actuating the two valves in a manner forproducing a particular desired operation thereof,'which means are adjustable for determining the relative movement imparted to the valves.

With these and other objects in view, my invention consists in the construction, arrangement and combination of the various parts of my device and in the practice of my process, whereby the objects contemplated: are attained, as hereinafter more fully setforth, pointed out in my"* claims, and illustrated in thev accompanying drawings, in which: i

Figure 1 shows a side. elevation of a carburetor structure embodying my invention, parts being shown in' sect-ion and parts being broken away.

Figure 2 shows a vertical, sectional view of the carburetor structurev taken at right an les to the view shown in Figure 1.

Figure 3 shows a top or plan viewof the structure.

- Figure 4 shows a detail view of the auxiliaryvalve mechanism. I I

In the accompanying drawings, I have used the reference numeral 10 to indicate generally a tubular air and fuel passage forming the body of my improved carburotor, e

One end of the carburetor has the flange 11. whereby the carburetor may be connected with the intake manifold.

It will be noted that the carburetor is slightly enlarged for a portion of its length,

- as at A, when compared with the portion B in order to permit the use in the portion A of the parts hereinafter described as being therein. without thereby reducing the capacitv ofvthe fuel and air passage below thecapacity of the portion B; which is determined by the size and type of the engine. I At the side of the portion A of the carburetor, there is an opening 12, for which there is provided a suitable cover plate 13,secured" to the body of the carburetor by. means of screws 14 or the like.

The plate 13 has formed therein a compressed air conduit 15, projected both outwardly and inwardly with relation to the plate, and having at its inner end an upward extension 16.

Connected with the outer end of the conduit 15-is a compressed air pipe 17, which conducts air from a source of compressed air supply, such for instance as the tank 18.

It will be understood that air is' maintained in the tank 18 under pressure" in any suitable way.

Formed on the plate 13 and extending both inwardly and outwardly is a fuel conduit 19 in the, outer portion of which is a valve seat 20. Screwed into the conduit 19 is a needle valve stem 21, having the value 22 arranged to coact with the valve seat 20.

Extending through/the carburetor body is the stem 23 on which within the portion A of the carburetor body'between the air intake end thereof and the plate 13 is an ordinary throttle valve 24. On the stem 23 is a controlling arm 25. Mounted onthe lower end of the carburetor body 10 by means of set screws 26lis a shorter intake pipe 27 in which is a choke valve 28 of the butterfly type having the stem 29 on which is a controlling arm 30.

On one end of the stem 23' of the throttle valve 24 is mounted a hub 31. On the hub 31 is a-bar 32 mounted in an elongated slot 33 in a pulley 34. Screws 35 are mounted in the pulley 34 as shown in Figure 2, and extended into a screw-threaded opening 36 in the bar 32, so that by adjustment of the screws the pulley 34 may be adjusted eccentrically of the stem 23; i

On the stem 21 is mounted a hub or the like 37 having at one end a'flange 38. In the flange 38 are arcuate holes 39.

Mounted on the hub 37 isan annular pulley member 40, Screws 41 extend through the slots 39 into the pulley member 40.

By loosening the screw bolts 41, it will be menthat thepulley member 40 may be adiustedrotatablv on the'hub 37. o, 1 belt 42 preferably metallic is mounted on the pulleys 34 and 40 and held in fixed position with relation to the pulley 34 by means of setscrews 43 and 44.

In the belt 42 is a tension spring 45.

The adjustment of the pulley 40 on the hub 37 and the stem 21 permits adjustment of the needle valve 22 with relation to the throttle valve 24.

It is, of course, known that it is desirable to be able to regulate the relative motion of the throttle valve and needle valve. This relative adjustment is accomplished partially by making the pulleys 34 and 40 of different diameters.

During the first part of the opening movement of the throttle valve of the butterfly type, the movement of the valve through a certain number of degrees does not open the air passage so much as does the movement of the throttle valve through the same number of degrees farther along in the opening movement.

In order to provide for a more rapid opening of the needle valve during the latter movement of the throttle valve, I have provided the eccentric mounting of the pulley 34.

Mounted on the side of the carburetor is a floatchamber 46. which may be of the usual type and which is connected by a tube 47 with the'passage 19.

' A fuel pipe 48 leads from the passage 19 through the bottom of the extension 16 to a pointsubstantially flush with the discharge end of the extension 16, as shown in Figure 2.

I will now explain briefly the process, which may be employed with my carburetor structure above described. i

The parts are so constructed and arranged that the dischargeend of the upward extension 16 of the conduit 15 is above the normal level of the fuel in the float chamber 46.

Fuel is supplied from the float chamber to the conduit 19 and the fuel pipe 48.

Compressed air is supplied from the tank 18 through the pipe 17 to the conduit 15 and the extension 16 around the pipe 48.

This air leaving the extension 16 at greater than atmospheric pressure forms a pocket over-the upper part or discharge end of the pipe 48 in which the air has less pressure than the atmosphere, and as a result atmospheric pressure causes fuel to rise in the pipe 48 until it'is taken off by the current of compressed air and thoroughly atomized thereby. I

I find that the use of air under greater than atmospheric pressure accomplishes a better atomization of the fuel than do the ordinary methods.

I have provided in connection with the structure already described an auxiliary fuel supply structure.

The portion A of the carburetor 10 has an opening 49. which may be closed by a de- 'tachable cover plate 50.

The cover plate 50 has a conduit 51pmjecting into the carburetor body and provided with an upward extension 52.

' eration of the valve 55.

A fuel tube 53 conducts fuel from the float chamber 46 to the conduit 51. The upper end of the extension 52 has a valve seat 54. A needle valve 55 coacts with that valve seat.

The upper end of the needle valve 55 is supported by a downdardly, opening yoke .56. which projects substantially below the passage 51 and has on its lower end a disc 57. Screwed into the lower part of, the passage 51 is a post or the like 58. which extends through the disc 57 for permitting sliding movement of the disc on the post.'

, On the post 58 are adjustable nuts 59. On the post 58 between the disc 57 and the adjustable nuts 59 is an extension coil spring 60, which normally yieldingly holds the valve 55 seated.

The nuts 59 may be adjusted for varying the tension of the spring 60. p

A stop pin 61 limits the upward movement of the disc 57 to prevent any accidental complete displacement of the valve 55.

The parts just described are of such size and proportions that any ordinary pressure on the disc 57 from below would not compress the spring 60 and open the valve 55, but when the device is in use on an engine, the impact of the swiftly moving current of air passing through the carburetor body acts on the disc 57, so that when the engine is traveling at high speed and the movement of air is rapid enough, the valve 55 is raised for admitting an auxiliary supply of fuel to the carburetor. It should be noticed in this connection. that the discharge end of the extension, 52 is below the fuel level in the. float chamber 46.

It might perhaps be mentioned that the compressed air is of comparatively small volume, so that it will not substantially reduce the vacuum created by the engine in the carburetor body nor interfere with the 0p- I simply provide a constant jet which needs no regulation. Not enough air is su plied even to 'keep theengine idling without additional air. Thesupply is constant.

When the engine speeds up too. higher speed after the throttle valve has been moved to wide open position, more air is re uired in proportion to the increase in spee and the air should flow in greater velocity in order to atomize sufficient fuel for proper carburetion. This higher air velocity ocours on acount of the greater suction from the engine and the impact of the moving current of air with which the auxiliary fuel valve is operatedin proportion to'the increase in the velocity of the air. I

Some changes may be made in the details of 'the construction and arrangement of my improved carburetor without departing from the real spirit and purpose of my invention, and it is my intention-to cover by my claims thereon, any modified forms of structure or use of mechanical equivalents,

which may be reasonably included within their scope.

It is also my intention to cover by my process claims, any modifications which may come within the spirit of my invention and the scope of such claims.

- In the following claims, I have used the term mixing chamber for the carburetor body for convenience of'terminology.

I claim as my invention:

1. In a carburetor structure, a throttle valve having a stem. a needle valve having a stem and means for operatively connecting the said stems for imparting rotation from one stem to the other at a rate of speed relatively varying according to the position-of rotation of the actuating stem, the actuated stem having a screw-threaded mounting, said means having an adjustable connection with the actuated stem, and an adjustable connection with the actuating stem.

2.In a carburetor structure, a throttle valve having a stem, a needle valve having a stem and means for operatively connecting the said stems forimparting rotation from one stem to the other at a rate of speed relatively "arying according to the position of rotation of the actuating stem, the actuated stem having a screw-threaded mounting, said means having an adjustable connection with the actuated stem rotatably thereof, and an adjustable connection with the actuating stem radially thereof.

3. In a carburetor structure, a pair of valves having parallel stems, means for imparting rotation from one stem to the other, comprising discs mounted on said stems, an endless member mounted on said discs, one of saiddiscs being arranged eccentrically on its stem, and a spring included in said endless member for compensating for the change in the length thereof due to the eccentricity of the eccentricallyarranged disc.

4. In a carburetor structure, a pair of valves having parallel stems, means for imparting rotation from one stem to the other,

comprising discs mounted on said stems, and endless member mounted on said discs, one

endless member mounted on said discs, one of said dlSCS being mounted for GCCGIltIlC adjustment on its stem, said endless member being fixed to each disc, and aspring included in said endless member for compensating for the change in the length thereof due to the eccentricity of the eccentrically arranged disc.

6. In a carburetor structure, a pair of valves having parallel stems.- means for imparting rotation from one stem to the other, comprising discs mounted on said stems, an endless member mounted on said discs, one of said discs being mounted for eccentric adjustment on its stem, and a spring included in said endless member for compen-v sating for the change in the length thereof due to the eccentricity of the eccentrically arranged disc. said endless member being fixed to each disc, the other of said discs being mounted for rotatable adjustmenton its stem.

Des Moines, Iowa, February 19, 1923. j ARVID R. NELSON. 

